Tracked climbing machine with compliant suspension apparatus

ABSTRACT

A tracked climbing vehicle containing a compliant suspension apparatus to prescribe the distribution of forces on the adhering members in the tracked climbing machine. The compliant suspension apparatus is configured to negotiate irregularities in a climbing-surface without the vehicle tracks losing full surface contact and adhesion by distributing the loads from the climbing machine chassis to the adhering traction members in a specific prescribed fashion. The apparatus thus avoids exceeding the allowable force in any adhering traction member and significantly improves the performance of the climbing machine.

This application is a continuation of U.S. application Ser. No.12/657,962, filed Jan. 29, 2010, issued as U.S. Pat. No. 8,567,536, andis entitled to that filing date for priority. The specification, figuresand complete disclosure of U.S. application Ser. No. 12/657,962 isincorporated herein by specific reference for all purposes.

FIELD OF INVENTION

This invention relates to a robotic tracked vehicle. More specifically,this invention relates to a robotic tracked vehicle for climbing withendless tracks.

BACKGROUND OF THE INVENTION

Self-propelled climbing machines or vehicles may be employed to performremote operations in locations that are difficult for, or incompatiblewith, human presence or access. One example is a vehicle that can travelover a steel surface in a vertical, horizontal or upside-downconfiguration, such as on tanks, pipes, boiler walls or ship hulls, andalso carry equipment to perform manufacture, maintenance or inspectionfunctions. There are many structures which require maintenance, repair,inspection or manufacturing operations that could be performed by aremote machine in a tele-operated or autonomous fashion.

Numerous vehicles have been proposed to travel over inclined surfaces,and even operate upside down. These vehicles generally employ legs,wheels, or endless-tracks. Vehicles using endless-tracks provide severaladvantages, in particular the potential for a large area of contactbetween the vehicle and contact surface. Endless-tracks provideexceptional potential for large-area surface contact between thetrack-members (for example magnets) and the climbing-surface.

This invention concerns vehicles of the endless-track type with magnetictrack-members incorporated in the endless-tracks. These vehicles areintended to operate on significant inclines, or upside down and/or onsurfaces having, alone or in combination, concave, convex or irregularcontours.

The endless-track type climbing vehicles available in previoustechnologies may have adhering track-members attached to the tracks andemploy an endless-track of specific properties, to include very hightensile stiffness of the endless-track itself, in the axial direction ofthe track, but negligible stiffness in all transverse directions andnegligible stiffness with respect to in bending. This creates atechnological disadvantage in that the track in such cases is capable ofsupporting tensile forces, but has only minimal stiffness in bending orin tension for small angles. Accordingly, it can support only negligibleloads in any other direction, cannot support sheer side loads, andcannot support compressive loads.

For such a climbing vehicle to remain in equilibrium in any givenposition and orientation on a climbing-surface, forces affecting thatequilibrium must be transferred from the climbing-surface to thevehicle. For a simple track type climbing vehicle, these forces aretransferred from the track-members to the vehicle chassis throughtensions in the endless-track. This would ideally allow theendless-track to accommodate irregular climbing surfaces, but wouldconcurrently result in localizing on the outer adhering track-membersall of, or a majority of, the forces necessary to affect and maintainpositional and orientational equilibrium with the climbing surface.

The surface normal forces are a subset of the total forces that arerequired to maintain vehicle equilibrium on the climbing-surface. Thesurface normal forces are perpendicular to the climbing-surface and arerequired for equilibrium. To distribute this subset of forces in amanner intended to maintain equilibrium between the climbing vehicle andthe climbing-surface, one might envision employment of a rigid guidesection that slidably connects to the endless-track. But this approachcreates its own set of disadvantages in that it causes the surfacenormal forces to be localized on individual adhering track-memberswhenever and wherever climbing-surface irregularities are encountered.

The performance of an endless-track type climbing vehicle dependsdirectly on the effective ability of the track, and accordingly, thetrack-members, to adhere to the climbing-surface. Numerous patents existfor climbing vehicles containing endless-tracks with adheringtrack-members incorporated into the tracks. One shortcoming of theseprevious technologies is their universal lack of a means to distributethe load among these adhering track-members in a manner that canaccommodate a wide variety of surface geometries. Creation of such aload distribution means would significantly improve the performance ofthese climbing vehicles, and is, therefore, a desirable advancement inthe art. As is detailed below, previous technologies do not provideeffective means to distribute the load among a plurality of adheringtrack-members.

The following discussion details and contrasts the instant art withillustrative examples of previous technologies and their associatedshortcomings that the instant art overcomes.

U.S. Pat. No. 5,894,901, by Awamura, incorporated herein by specificreference for all purposes, presents a traditional suspension systemconsisting of a plurality of press wheels equipped with elastic members(springs). These are capable of providing adjustment to the adheringmembers directed in to the climbing-surface only. The device provides,in contrast to the instant art, no means to compensate for, or tointegrate, any other forces or balance adjustments. Although, as doesthe instant art, the Awamura device includes magnets, an endless-track,and a suspension system, as designed, it only makes provision toadjustments necessary to push the magnets into contact with theclimbing-surface. The device is equipped with auxiliary wheels, eachwheel having a suspension supported by the vehicle body, pressing thewheel against the endless-track. These wheels are each supported by anelastic member in communication with the vehicle chassis. This is incontrast to the instant applicant's use of a compliant beam guide andsupport which automatically adjusts to balance the load carried and tomaximize traction.

U.S. Pat. No. 5,435,405 by Schempf, et al., incorporated herein byspecific reference for all purposes, teaches a reconfigurable mobilerobot with magnetic tracks. In contrast to the instant art, which usespermanently active magnets in the tracks, Schempf teaches a magneticsystem that can be activated and deactivated in the propulsion tracks.In further contrast, no guide, rigid or otherwise, is mentioned withrespect to the endless-track. Finally, unlike the instant art, the trackappears to have no track-guide.

U.S. Pat. No. 4,789,037 by Kneebone, incorporated herein by specificreference for all purposes, uses two or more endless-tracks withplurality of permanent magnetic adhering-members. Each adhering-membercomprises a permanent magnet sandwiched between magnetic metal plates.The magnet does not, itself, contact the climbing-surface, but contactsonly these metal plates. As taught, it does allow pivotal rocking motionof track assemblies relative to the vehicle body, for negotiating unevenor curved surfaces, the track assemblies comprising, for each trackunit, two laterally-spaced chains, each forming an endless-member. Thedevice also uses a pump in the center of the body to apply additionalupward or downward pressure to press the tracks onto theclimbing-surface, and does teach a fan to create suction force normal tothe climbing-surface. But the patent mentions no sort of trackguide,rigid or otherwise.

U.S. Pat. No. 5,884,642 by Broadbent, incorporated herein by specificreference for all purposes, teaches endless-tracks with plurality ofmagnetic sections, each tread using four rare earth magnetic segments,adjacent treads being oriented in opposing polarities. It does not,however, discuss any type of guide for the tracks, nor automatic balancecontrol or adjustment.

U.S. Pat. No. 4,828,059 by Naito, et al., incorporated herein byspecific reference for all purposes, employs a track guide that is usedonly to engage and disengage track magnets from climbing-surfaces.Locations of loads carried by the Naito device are limited to remainingwithin the upper and lower planes of the endless propulsion tracks. Itemploys a plurality of permanent magnets on outer surface of crawlertracks and has a guidance device on crawler tracks for restraining thereleasing crawler track from moving relative to crawler body indirection normal to traveling plane of magnets. It also includes a trackcontrol mechanism so designed such that the guidance device can restrainor release motion of the track to the main body in a direction normal tothe surface. When this guide load is released, the load is essentiallytransferred in its entirety, to only the end magnets of the tracks.

U.S. Pat. No. 5,487,440 by Seemann, incorporated herein by specificreference for all purposes, presents a rigid guide, and a pair ofparallel, endless-tracks equipped with suction cup feet. These tracksslide along a grooved structure that allows for communication between avacuum pump and those suction cups which are positioned for contact withthe climbing-surface. It makes little or no provision for significantsurface irregularities.

U.S. Pat. No. 6,672,413 B2 by Moore, et al., incorporated herein byspecific reference for all purposes, describes a remote controlledinspection vehicle utilizing magnetic adhesion to traversenon-horizontal, non-flat, ferromagnetic surfaces. Although this deviceemploys magnets to adhere to the climbing-surface, no magnets areattached to, or guided by a track. The magnets are, rather, attacheddirectly to the vehicle. The track comprises modules each of whichcontains a permanent magnet that the endless-track surrounds. Thesemodules are so constructed as to pivot about longitudinal axes in anattempt to conform to pipes or other irregularities.

Thus, an invention such as described herein, that distributes the forcesrequired to maintain equilibrium between the vehicle andclimbing-surface during operation among a plurality of adheringtrack-members, is novel to the state of art and is usefully and directlyapplicable to climbing vehicles having, or requiring, adheringtrack-members incorporated in endless-tracks. The herein taught artcomprises a compliant suspension apparatus that distributes stiffness(and correspondingly the forces of equilibrium) relative to theplurality of adhering track-members.

SUMMARY OF INVENTION

In various embodiments, the present invention comprises a trackedclimbing machine having one or more revolving or cyclical grippingdevices with adhering track-members. The revolving or cyclical grippingdevice is preferably in the form of one or more closed or endless,tracks, chains, belts, or cables upon the exterior of which thepreviously mentioned adhering track-members are mounted. This trackedvehicle can climb vertical surfaces and overhangs, and negotiate surfaceirregularities, and in doing so, prevent its tracks from losing fullsurface contact and adhesion.

Its innovations are particularly useful in transiting, ascending andotherwise negotiating unprepared boiler sides, submarine hulls, shipssides, towers and other ferrous structures to perform automated orremotely controlled inspection, maintenance, and cleaning tasks thatcould not otherwise be accomplished. The device is notably adept atclimbing vertical surfaces and overhangs and it is able to negotiatesurface irregularities without its tracks losing full surface contactand adhesion. It moves and climbs in a manner employing multiple feet,preferably aligned in two or more columns or tracks, by applying,adjusting, and releasing each individually gripping foot in response towhatever surface contour may be encountered by that particular foot.

A significant advance introduced by this technology is the bias devicesinstalled along the compliant beam. These devices exert forces on thebeam, in such a way as to distribute the pressure of the track in auniform manner, even when the transited surface is non-planar. Thisparticularly improves overall track performance when transiting smallbumps or hummocks on the surface.

Further objects and advantages of the present invention will becomeapparent from the following descriptions, taken in connection with theaccompanying drawings, wherein, by way of illustration and example, anembodiment of the present invention is disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings constitute a part of this specification and includeexemplary embodiments to the invention, which may be embodied in variousforms. It is to be understood that in some instances various aspects ofthe invention may be shown exaggerated or enlarged to facilitate anunderstanding of the invention.

FIG. 1 is an isometric view of the climbing vehicle composed of thevehicle chassis, two track-modules, and endless-track.

FIG. 2 is a front view of the climbing vehicle showing a front view ofthe vehicle chassis, track-modules, and endless-track.

FIG. 3 is an isometric view of a single track-module showing theendless-track and adhering track-members.

FIG. 4 is an isometric view of a single track-module with the exteriorcover cut away showing the compliant suspension apparatus consisting ofcompliant beam member, fore tangential guide link, aft tangential guidelink, contour-following bias-devices, fore, mid and aft bias adjusterand tensioning mechanism. Also shown in FIG. 4 are the track drivecomponents: i.e., drive-sprocket, track-sprocket, drive-motor, andtransmission.

FIG. 5 shows the primary components of the compliant suspensionapparatus isolated from the track-module.

FIG. 6 shows a cross-sectional end-view of the slidable connectionbetween the compliant beam member, the endless-track, and the slidingtrack-member, guided through guide slot and also of the support block,magnetic adhering track-member, and the connection between the adheringtrack-member and the endless-track.

FIGS. 7, 8 and 9 are side views of the device moving in direction D1,encountering an irregularity (CI) in a climbing-surface (CS), alsoshowing operation of the compliant suspension apparatus.

FIG. 10 shows a diagram of the climbing-surface (CS) with compliantbeam. A basis set of directions are defined at a point along thecompliant beam as: u1, a unit axis normal to the climbing surface (CS);u2, along the axis of the endless-track at this point; and u3, theright-hand axis of the frame.

LIST OF NUMBERED ELEMENTS

-   101 vehicle chassis-   101 a chassis payload-rack-   102 a port side track-module-   102 b starboard side track-module-   103 endless-track-   103 a track sliding-members-   104 adhering track-members-   105 compliant beam-   106 fore tangential guide-linkage-   107 aft tangential guide-linkage-   108 contour-following bias-device-   108 a fore contour-following bias-device-   108 b midship's contour-following bias-device-   108 c aft contour-following bias-device-   109 drive-sprocket-   110 track-sprocket-   111 drive-motor-   112 transmission-   113 guide-slot-   114 drive-sprocket axle-   115 track-sprocket axle-   116 compliant suspension apparatus-   118 tensioning mechanism-   119 magnet-   120 support-block-   121 a fore bias-adjuster-   121 b mid bias-adjuster-   121 c aft bias-adjuster-   D1 direction of motion-   CS climbing-surface-   CI contour or irregularity-   u1 axis u1 normal to the climbing-surface CS-   u2 axis u2, in the plane of the climbing-surface CS and normal to    the axis of the direction of movement endless-track-   u3 axis along track direction of motion D1-   R1 first independent track-module axes of limited rotational freedom    about an axis in the plane of the climbing-surface CS-   R2 second independent track-module axes of limited rotational    freedom about an axis in the plane normal to that of the    climbing-surface CS

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Detailed descriptions of exemplary embodiments are provided herein. Itis to be understood that the present invention may be embodied invarious forms. Therefore, specific details disclosed herein are not tobe interpreted as limiting, but rather as a basis for the claims and asa representative basis for teaching one skilled in the art to employ thepresent invention in virtually any appropriately detailed system,structure or manner.

In one exemplary embodiment, as seen in FIGS. 1 and 2, the presentinvention comprises a self-propelled work vehicle for traversing asurface, comprised of a vehicle chassis 101, to which a payload may beattached. The vehicle is equipped with one or more track-modules 102 a,102 b that support the vehicle chassis 101, and which supportendless-tracks 103, these tracks 103 incorporating a plurality ofmagnetic track-members 104 spaced along each endless-track 103. Thechassis 101 may be adapted to carry a multiplicity of payloads, tools orequipment.

As seen in FIGS. 3, 4, 7, 8 and 9, the endless-track 103 withtrack-members 104 cyclically moves in such a way as to providelocomotive force. When the vehicle is in motion, portions of the trackare constantly cycling through a traction-portion of its cycle, whereinthey make contact with the climbing-surface (CS). As seen in FIGS. 4, 5,7, 8 and 9, a compliant suspension apparatus 116 incorporates acompliant beam member 105 to which the revolving or cyclical track 103is slidably connected.

In short summary of the device and its operation, the climbing vehicleand chassis 101 are subject to a variety of forces, includinggravitational and dynamic loads associated with the vehicle and payloadmotion, as well as to forces generated by the operation of the toolingor equipment attached to the vehicle. These forces are to be transferredto the climbing-surface (CS) through the endless-track 103 and adheringtrack-members 104, preferably permanent magnets 119. The forces arecompensated for by the compliant suspension apparatus, and bias devices,adjusted according to Hooke's law which relates force, displacement andstiffness. This adjustment may be applied automatically or manually.

The suspension and compliant beam apparatus of this device dictate howthe above forces are transmitted from the vehicle chassis 101 to theadhering track-members 104 over a wide range of surface irregularitiesor contours (CI) of the climbing-surface (CS). This apparatus, acombination mechanism of a compliant beam 105 slidably connected to thetrack 103, rigid-body members, and bias-devices or springs 108,maximizes track contact with the climbing-surface (CS) in a mannerdifferent from and superior to previous technologies and permits theflexible endless-track to propel and support a rigid vehicle chassis ina more continuous, and therefore more effective manner.

The apparatus which achieves the above prescribed stiffness orcompliance consists of three primary components. These components, inthe embodiment shown in FIG. 5, are as follows: the one or morecompliant beams 105; the rigid-body tangential guide-linkages 106, 107;and the contour-following bias-device elements 108. A compliant beam 105is slidably attached to the endless-track 103. The compliant beam's 105geometric and material properties are established to be compatible withthe geometry of a climbing-surface (CS) having a wide range of contoursor irregularities.

The compliant beam 105 of FIG. 10 is conjugate and slidably connected tothe endless-track (not shown) and prescribes five specific stiffness (orcompliance) components between the climbing-surface (CS) and theclimbing machine body. These include all axis cardinal directions inthree-dimensional space, except the direction of movement D1 of theendless-track. Since the compliant apparatus is slidably connected tothe endless-track, no stiffness is prescribed on that axis of theendless-track.

Listing the components addressed, they are, as shown in FIG. 10:

1) translational stiffness along unit axis u1 normal to theclimbing-surface (CS);

2) translational stiffness along unit axis u2, in the plane of theclimbing-surface (CS) and normal to the axis of the endless-track;

3) rotational stiffness about u1 normal to the climbing-surface (CS);

4) rotational stiffness about u2, an axis in the plane of theclimbing-surface (CS) and normal to the axis of the endless-track; and

5) rotational stiffness about u3, the axis of the endless-track.

The linear stiffness along u1 is prescribed along the entire track touniformly distribute the forces on the adhering track-members. Thelinear stiffness along u2 is prescribed to limit transverse deflectionof the endless-track (high stiffness). The rotational stiffness about u1is prescribed to limit rotation of the endless-track (high stiffness)about an axis normal to the climbing-surface (CS). The rotationalstiffness about u2 is prescribed to allow low stiffness along the centerportion of the endless-track to accommodate contours or irregularitiesin the climbing-surface (CS) and high stiffness where the endless-trackengages the track sprockets.

The rotational stiffness about u3 is prescribed to allow low stiffnessalong the center portion of the endless-track to accommodate contours orirregularities in the climbing-surface (CS), and high stiffness wherethe endless-track engages the track-sprockets.

As noted above, the compliant beam 105 provides a surface conjugate tothe endless-track 103 in a slidable connection. The fore tangentialguide-linkage 106 enforces the stiffness and geometry of the compliantbeam 105 conjugate to the endless-track 103 at the point where theendless-track 103 engages the drive-sprocket 109. The aft tangentialguide-linkage 107 enforces the stiffness and geometry of the compliantbeam 105 conjugate to the endless-track 103 at the point where theendless-track 103 engages the track-sprocket 110. The contour-followingbias-device members 108 a, 108 b, 108 c prescribe the stiffness of thecompliant beam 105 in the u1 direction to more uniformly distribute theforces in the adhering track-members 104.

This compliant beam member 105 is so contrived and adjusted, by means ofcontour following bias devices 108, 108 b, 108 c and adjustors 121 a,121 b, 121 c (see FIG. 4). These bias-devices 108 are located at pointsalong the compliant beam 105, such that each bias-device 108 exertsforce upon the compliant beam 105 at its particular point on the beam105. This changes the force of the track 103 against the transitedsurface (CS) at that particular tension point. The change of force atthis point creates a force to pull portions of the track 103 more firmlyagainst the transited surface (CS) by promoting deformation of thecompliant beam 105 to conform with the topography of the surface (CS)being transited.

This causes track 103 force against the transited surface (CS), to bemore equally distributed, promoting increased surface contact of alladhering-members along the rest of the track, thereby maximizing thearea over which the adhering members of the endless-track contact thetransited surface and distributing the force along the track. Thebenefits of these effects are particularly notable when and where thetrack encounters small bumps, hummocks or other irregularities (CI) inthe climbing surface (CS).

A useful way of understanding this innovation is to imagine thisclimbing machine, inverted, transiting an overhead surface (CS),essentially clinging magnetically to, and hanging from, the ceiling. Insuch a position, one can see the benefit of distributing the load alongthe track 103 through the bias devices and simultaneously ensuringpositive pressure between the track 103 and the overhead surface (CS) ateach end of the track. In the same way, referring to FIG. 7-9, one cansee that as the device passes over an irregularity (CI), the portion oftrack 103 not in contact with the irregularity (CI) would tend to bepushed out of contact with the climbing-surface (CS), were it not forthe bias devices 108. But because of the tension exerted by the biasdevice 108 on the track 103 in the vicinity of the irregularity (CI),the rest of the track 103 tends to be pulled more firmly into contactwith the climbing-surface (CS).

Thus the track 103 and the compliant beam 105, tend to better adapt tocontours (CI) of climbing-surfaces (CS) in such a way as to allow themagnetically adhering track-members 104 to maintain traction on thesurface (CS). The system is powered by the drive-motor 111 andtransmission 112 that propels the track via one or more drive-sprockets109.

Referring to FIG. 2, the chassis 101 is attached to the track-modules102 a and 102 b in a manner that allows two degrees of rotary movementbetween each track-module 102 a, 102 b and the chassis 101. As shown inFIG. 1, this movement is about two independent axes R1 being an axis inthe plane of the climbing-surface, and R2 being an axis normal to theclimbing-surface (CS).

Referring to FIG. 6, the adhering track-members 104 each are preferablycomprised of a magnet 119 located in a support-block 120. Referring toFIGS. 3 and 4, the support-block 120 is connected to respective sectionsof the endless-track 103, and sliding member 103 a in the guide-slot113, so that necessary relative motion is available to allow theassembly of endless-track 103 and adhering track-members 104 to passalong and around the path described by the location of the drive andtrack-sprockets, 109 and 110, the track tensioning mechanism 118, andthe guide-slots 113, in the compliant beam member 105.

Referring to FIGS. 3 and 4, a compliant suspension apparatus 116 iscontained within the track-modules 102 a and 102 b. The compliantsuspension apparatus 116 consists of compliant beam member 105, foretangential guide-linkage 106, aft tangential guide-linkage 107, and aplurality of contour-following bias-devices 108 a, 108 b and 108 c.

The compliant beam member 105 is slidably connected to the endless-track103 through guide-slots 113. The fore tangential guide-linkage 106 isrigidly attached to the compliant beam member 105 and pivotallyconnected to the track-module 102 a at the drive-sprocket axle 114. Theaft tangential guide-linkage 107 is slidably connected to the compliantbeam member 105 and pivotally connected to the track-module 102 a at thetrack-sprocket axle 115.

The endless-track 103 engages the drive-sprocket 109 and track-sprocket110. The drive-sprocket 109 and track-sprocket 110 are pivotallyconnected at the drive-sprocket axle 114 and track-sprocket axle 115respectively to the track-module 102 a to permit pivotal movement of thedrive and track-sprockets, 109 and 110. The drive-sprocket 109 is drivenby a drive-motor 111 through a transmission 112. Each track-module 102a, 102 b is independently driven, allowing the vehicle to be propelledand steered by judicious control of speed and direction of thedrive-motor(s) 111.

The endless-track 103 engages the track tensioning mechanism 118. Thetrack tensioning mechanism 118 is pivotally connected to thetrack-module 102 a and is biased with a track-tension bias-device 118 toprovide tension in the endless-track 103, as the length of endless-track103 in contact with the climbing-surface (CS) varies according to thesurface irregularities or contours encountered (CI).

The forward external contour-following bias-device 108 a is pivotallyconnected to the compliant beam member 105 and pivotally connected tothe track-module 102 b. The aft contour-following bias-device 108 c ispivotally connected to the fore tangential guide-linkage 106 pivotallyconnected to the track-module 102 b. The aft contour-followingbias-device 108 is pivotally connected to the aft tangentialguide-linkage 107 and pivotally connected to the track-module 102 b asshown in FIG. 4.

In operation, the vehicle chassis 101 is positioned with track adheringmembers 104 in contact with a climbing-surface (CS). Then, thedrive-motor(s) 111 are activated.

Proceeding along the climbing-surface (CS), the adhering track-members104 make sequential contact, each in its turn, with the climbing-surface(CS), while the endless-track 103 slides along the compliant beam member105, thereby propelling the vehicle.

Referring to FIGS. 7-9, when a track adhering member 104 encounters anirregularity (CI) in the climbing-surface (CS), the vehicle andsuspension system ingeniously compensate for this surface irregularity(CI) with a high level of precision. Here an irregularity (CI) of theclimbing-surface (CS) is defined as any spatial departure of theclimbing-surface (CS) from a planar surface. Such surface irregularitiesmay be concave or convex, sharply defined protrusions or rifts, or acombination thereof

The means of this notably effective compensation are employed asfollows. The compliant beam portion 105 of the suspension deforms tomatch the contour of the climbing-surface irregularity (CI). Whiledeformed, the compliant beam 105 portion maintains its slidableconnection 103 a to the endless-track 120. The contour-followingbias-devices 108 a and 108 b maintain tension or compression between thedeformed compliant beam 105 and the rigid vehicle chassis 101 toward theclimbing-surface (CS). These forces keep the chassis 101 in positivecontact with the climbing-surface (CS).

This in turn forces the fore track-sprocket 109 toward with theclimbing-surface (CS). The fore tangential guide-linkage 106 thenmaintains contact of the compliant beam portion of the suspension andthe leading adhering tractive members 104, guiding the compliant beam105 to deform to match irregularities in the climbing-surface (CS).

To better understand the device in negotiation of a climbing-surface(CS), FIG. 7 shows a side view of the device climbing a surface (CS)prior to the surface irregularity (CI), and can be compared to FIG. 8.FIG. 9 shows a similar view of the device on a climbing-surface (CS)that has a significant contour or irregularity (CI) to be negotiated.The function of the compliant beam member 105 as it adapts to theclimbing-surface (CS) contours and irregularities (CI) is demonstrated.

Also illustrated are the adaptive functions of the contour-followingbias-devices 108 a, 108 b and 108 c in supporting the compliant beammember 105 while linking the compliant beam member 105 to the chassis101, and the adaptive function of the tangential guide-linkages 106 and107 and of the tensioning mechanism 118. Note particularly how thetensioning mechanism 118 adjusts to allow a greater total area ofcontact for the endless-track 103 to conform to brief climbing-surface(CS) contours and irregularities (CI).

Thus, it should be understood that the embodiments and examplesdescribed herein have been chosen and described in order to bestillustrate the principles of the invention and its practicalapplications to thereby enable one of ordinary skill in the art to bestutilize the invention in various embodiments and with variousmodifications as are suited for particular uses contemplated. Eventhough specific embodiments of this invention have been described, theyare not to be taken as exhaustive. There are several variations thatwill be apparent to those skilled in the art.

What is claimed is:
 1. A tracked vehicle, comprising, a vehicle chassis;a first track for propelling said vehicle, said first track comprising aplurality of adhering track members adapted to provide traction whensaid vehicle transits a surface; and a first compliant beam in directcontact with and slidably connected to said first track and furtherconnected by one or more rigid body members, bias devices, orcombinations thereof, to said chassis, wherein said compliant beamtransiently deforms to cause said adhering track members to preservecontact with said surface.
 2. The tracked vehicle of claim 1, whereinsaid one or more bias devices are located at one or more points alongthe compliant beam, and are adapted to exert a pulling or pushing forceto cause the compliant beam to transiently deform thereby resulting inequalized distribution of track pressure against said surface.
 3. Thetracked vehicle of claim 2, wherein said one or more bias devices areadjustable.
 4. The tracked vehicle of claim 1, wherein the transientdeformation of the compliant beam maximizes the contact area between theadhering track members and said surface.
 5. The tracked vehicle of claim1, further wherein said one or more rigid body members comprise one ormore tangential guide-linkages, wherein said guide-linkages link thecompliant beam to said vehicle chassis.
 6. The tracked vehicle of claim5, wherein said guide-linkages join to the vehicle chassis bypivot-points.
 7. The tracked vehicle of claim 6, wherein theguide-linkages rotate in a plane normal to the surface being transited.8. The tracked vehicle of claim 5, wherein said guide-linkages join tothe compliant beam by pivot-points, upon which the guide-linkages mayrotate or slide.
 9. The tracked vehicle of claim 1, further comprising adrive mechanism.
 10. The tracked vehicle of claim 1, further comprisinga second track and second unitary compliant beam, wherein the firsttrack and second track are located on opposite sides of the vehiclechassis.
 11. The tracked vehicle of claim 1, further comprising apayload carrying mechanism.
 12. A suspension and movement apparatus fora tracked vehicle with a chassis, comprising: at least one track forpropelling said vehicle, said track comprising a plurality of adheringtrack members adapted to provide traction when said vehicle transits asurface; and a compliant beam in direct contact with and slidablyconnected to said track and further connected by one or more rigid bodymembers, bias devices, or combinations thereof, to said chassis, whereinsaid compliant beam transiently deforms to cause said adhering trackmembers to preserve contact with said surface.
 13. The apparatus ofclaim 12, wherein said one or more bias devices are located at one ormore points along the compliant beam, and are adapted to exert a pullingor pushing force to cause the compliant beam to transiently deform. 14.The apparatus of claim 13, wherein said one or more bias devices areadjustable.
 15. The apparatus of claim 12, further wherein said one ormore rigid body members comprise one or more tangential guide-linkages,wherein said guide-linkages link the compliant beam to the vehiclechassis.
 16. The apparatus of claim 15, wherein said guide-linkages jointo the compliant beam by pivot-points, upon which the guide-linkages mayrotate or slide.